Autonomous vehicles, such as vehicles that do not require a human driver, can be used to aid in the transport of passengers or items from one location to another. Such vehicles may operate in a fully autonomous mode where passengers may provide some initial input, such as a pickup or destination location, and the vehicle maneuvers itself to that location controlled by a control system.
On rare occasions, the control system may detect errors in the propulsion system caused by a lack of acceleration or unintended acceleration. For instance, mechanical failures or errors in signal processing may result in a total loss of acceleration or even too much acceleration. The result may be a situation in which the vehicle's control computing devices are unable to safely maneuver the vehicle to reach a desired destination. Some vehicles may notify a driver and switch to a manual driving mode. However, if the driver is not responsive or a manual driving mode is not available (not operational or simply not a mode of the vehicle), this solution is ineffective.